System and method for secure and verified sharing of resources in a peer-to-peer network environment

ABSTRACT

A system and method for secure and verified sharing of resources in a peer-to-peer network environment to facilitate efficient use of bandwidth are disclosed. The method for securely sharing resources over a peer-to-peer network generally comprises broadcasting a request by a requesting peer for a resource over the peer-to-peer network where the resource is identified with a resource version identifier, receiving a response from a responding peer on the peer-to-peer network indicating that the responding peer has the requested resource, retrieving the requested resource from the responding peer, and verifying the retrieved resource by ensuring the retrieved resource contains the version identifier embedded therein. Preferably, the verifying also includes verifying a digital signature, such as a 1024-bit VeriSign digital certificate, of the retrieved resource to ensure integrity of the retrieved resource.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the priority benefit of U.S. Provisional PatentApplication Ser. No. 60/282,333, entitled “System and Method forEfficient Use of Bandwidth and Resources in a Peer-to-Peer NetworkEnvironment” and filed Apr. 6, 2001 and U.S. Provisional PatentApplication Ser. No. 60/298,681, entitled “System and Method forEfficient Updating of Virus Protection Software and Other Efficient Usesof Bandwidth and Resources in a Peer-to-Peer Network Environment” andfiled Jun. 15, 2001, both of which are incorporated herein by referencein their entireties.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to a system and method forefficient use of bandwidth and resources in a peer-to-peer networkenvironment. More specifically, a system and method for secure andverified sharing of resources in a peer-to-peer network environment tofacilitate efficient use of bandwidth are disclosed.

2. Description of Related Art

Conventionally, to obtain anti-virus product updates and/or signaturefiles, computers rely on a pull approach in which each client or servercomputer must retrieve the updated anti-virus file directly from asource via the Internet. For a computer network, a network administratormay allow anti-virus signature files to become out of date because thereare simply too many clients on the network for effective management.Alternatively, the network administrator may schedule the clients toautomatically pull the updated anti-virus file from the Internet wheneach client logs onto the computer. However, such an approach can resultin a bandwidth crunch such as in the early morning work hours when mostusers log onto their computers.

Connections to the Internet from within an organization, particularlyfrom a small to medium sized organization, may be relatively slow. Forexample, a small to medium sized business may share a single cable orDSL modem, a 56K modem, or an ISDN line. In contrast, in a typical workgroup interconnected via a LAN, connections on the LAN are generallymuch faster, the typical LAN being 100/TX (100 Mbps). Peer-to-peernetworks thus partially address the need for efficient use of bandwidthand resources in a computer network.

However, conventionally, peer-to-peer distribution is not secure and isparticularly susceptible to attacks since a desired resource or a fileon the network may be compromised as a file distributor does not havecontrol of the peer servers that are passing around copies of the fileon the network. This is of particular concern for files that are actualexecutable binaries and/or for files containing potentially criticaldata such as anti-virus product updates and signature files.Furthermore, for product updates such as anti-virus product updates, arequesting peer may not be able to determine whether the product fileson other peer computers are up-to-date or outdated.

Thus, it is desirable to provide a system and method for secure andverified sharing of resources in a peer-to-peer network environment tofacilitate efficient use of bandwidth to ensure that the shared file hasnot been compromised and/or is up-to-date. Such secure and verifiedsharing of resources over a peer-to-peer network ideally expands networkresource sharing into broader applications such as enterprise softwaremanagement and services.

SUMMARY OF THE INVENTION

A system and method for secure and verified sharing of resources in apeer-to-peer network environment to facilitate efficient use ofbandwidth are disclosed. The peering service system and methodfacilitate in spreading load amongst peers in a distributed networkinterconnected via a LAN in a smooth, secure and scalable way. Thepeering service provides security mechanisms to ensure that the sharedfile has not been compromised and/or is up-to-date. Preferably, theservice-enabled application, such as an updating application, implementsdigital signature security to verify the integrity of the retrieved datain order to ensure that the resource, such as an update, has not beencompromised. The service-enabled application preferably also implementsversion information security measure to ensure that the resource is anup-to-date or otherwise correct version.

It should be appreciated that the present invention can be implementedin numerous ways, including as a process, an apparatus, a system, adevice, a method, or a computer readable medium such as a computerreadable storage medium or a computer network wherein programinstructions are sent over optical or electronic communication lines.Several inventive embodiments of the present invention are describedbelow.

According to a preferred embodiment, a method for securely sharingresources over a peer-to-peer network generally comprises broadcasting arequest by a requesting peer for a resource over the peer-to-peernetwork where the resource is identified with a resource versionidentifier, receiving a response from a responding peer on thepeer-to-peer network indicating that the responding peer has therequested resource, retrieving the requested resource from theresponding peer, and verifying the retrieved resource by ensuring theretrieved resource contains the version identifier embedded therein.Preferably, the verifying also includes verifying a digital signature,such as a 1024-bit VeriSign digital certificate, of the retrievedresource to ensure integrity of the retrieved resource.

The method may further include retrieving a catalog containing a listingof resources, comparing the resource listing with resources installed atthe requesting peer to determine which resources are to be requestedover the peer-to-peer network, and requesting each such resource in aseparate transaction such that each such resource may be retrieved froma same or different responding peer.

According to another preferred embodiment, a product updating servicefor automatic and secure updating of a product installed at a node of apeer-to-peer network generally comprises automatically downloading acatalog containing a current listing of resources for the product at apredetermined time, comparing the listing with resources installed atthe node to determine which resources are to be requested, requestingeach such resource in a separate transaction over the peer-to-peernetwork, retrieving each resource from a peer in the peer-to-peernetwork or the Internet, and verifying each retrieved resource byensuring the retrieved resource contains a version identifier embeddedtherein.

According to yet another preferred embodiment, a method for providingsecure updating of a software product generally comprises providing forretrieval over the Internet a catalog containing a current listing ofresources for the product and providing for retrieval over the Internetthe resources for the product, each resource being identified with aresource version identifier and contains the resource version identifierembedded therein and/or contains a digital signatures such as a 1024-bitVeriSign digital certificate.

These and other features and advantages of the present invention will bepresented in more detail in the following detailed description and theaccompanying figures which illustrate by way of example the principlesof the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be readily understood by the followingdetailed description in conjunction with the accompanying drawings,wherein like reference numerals designate like structural elements, andin which:

FIG. 1 is a block diagram of an exemplary computer network suitable forimplementing a peering service in a peer-to-peer network to facilitateefficient use of bandwidth and resources;

FIG. 2 is a block diagram illustrating an exemplary peering servicesystem and method implemented at a node of the computer network of FIG.1;

FIG. 3 is a state diagram illustrating states of a typical peeringservice server in processing a request from a peering client in thepeer-to-peer network;

FIGS. 4A and 4B are alternative state diagrams illustrating states of atypical peering service client in requesting a resource over thepeer-to-peer network;

FIG. 5 is a flowchart illustrating a typical process of a peeringservice server in processing a request from a peering client in thepeer-to-peer network;

FIG. 6 is a flowchart illustrating a typical process of a peeringservice client in requesting a resource over the peer-to-peer network;

FIG. 7 is a flowchart illustrating a preferred embodiment of theretrieve step of FIG. 6 in more detail;

FIG. 8 is a flowchart illustrating an exemplary secure product updatingprocess implemented by a service-enabled product updating applicationover a peer-to-peer network;

FIG. 9 illustrates an example of a computer system that can be utilizedwith the various embodiments of method and processing described herein;and

FIG. 10 illustrates a system block diagram of the computer system ofFIG. 9.

DESCRIPTION OF SPECIFIC EMBODIMENTS

A system and method for secure and verified sharing of resources in apeer-to-peer network environment to facilitate efficient use ofbandwidth are disclosed. The peering service facilitates in spreadingload amongst peers in a distributed network interconnected via a LAN ina smooth, secure and scalable way. A service or an application that isservice-enabled may minimize or reduce the usage of, for example,Internet bandwidth by attempting to locate a local aliased copy of arequested resource residing within the peer-to-peer network. If a localaliased copy of the requested resource is located, the requestingcomputer may obtain the requested resources locally. Once the requestingcomputer obtains a copy of the requested resource, whether locally orremotely, the requesting computer may itself become a server for thealiased copy for subsequent requests for the resource.

The following description is presented to enable any person skilled inthe art to make and use the invention. Descriptions of specificembodiments and applications are provided only as examples and variousmodifications will be readily apparent to those skilled in the art. Thegeneral principles defined herein may be applied to other embodimentsand applications without departing from the spirit and scope of theinvention. Thus, the present invention is to be accorded the widestscope encompassing numerous alternatives, modifications and equivalentsconsistent with the principles and features disclosed herein. Forpurpose of clarity, details relating to technical material that is knownin the technical fields related to the invention have not been describedin detail so as not to unnecessarily obscure the present invention.

FIG. 1 is a block diagram of an exemplary computer network 100 suitablefor implementing the peering service in a peer-to-peer network tofacilitate efficient use of bandwidth and resources as described herein.In particular, the computer network 100 comprises nodes, computers, orworkstations 104A-E interconnected via a LAN 102. It is to be understoodthat the LAN 102 may be implemented using any suitable network mechanismincluding wire and wireless. In the exemplary computer network 100, onlytwo of the nodes 104D and 104E have access to the Internet.

FIG. 2 is a block diagram illustrating an exemplary peering servicesystem and method implemented at a node of the computer network ofFIG. 1. As shown, each node 104 provides the functionality of both aserver 106 and a client 110. The peering service system utilizes a port,such as port 1967, for transmitting directed or broadcast messages topeers on the network. The server preferably includes an embedded HTTPserver 108, typically a micro HTTP server. The HTTP server 108 allowsaliased URLs to be accessed by other peers on the network. The HTTPserver 108 preferably uses an obscure port such as port 6515 and ispreferably restricted to operations required to facilitate distributionof, for example, cached files and uploading of data or requests.

Typically, each node runs both the server and the client. However, eachnode may run only the client or the server. The peering system andmethod are preferably implemented as a peering service application(“service” or “service-enabled application”) or daemon process. It isnoted that a service-enabled application need not be a serviceapplication. For example, a service-enabled application may also referto a service-aware application that fires up, communicates with theservice and then shuts down interactively.

The peering system preferably provides a linkable client API library 112to facilitate communication between the peering service and anyservice-enabled applications. In one preferred embodiment, the peeringsystem may export the client API library 112 to any service-enabledapplication such that the service-enabled application may utilize thepeering service to discover any type of resource that can be identifiedwith a URL or URI, for example. Alternatively, a given application andthe peering service may be tightly coupled so as to eliminate the needfor the linkable client API library.

FIG. 3 is a state diagram illustrating states 120 of a typical peeringservice server in processing a given request from a peering client inthe peer-to-peer network. Initially, the service server is in an idlestate 122 while listening on a designated port for a broadcast requestmessage from a peer client on the network. When the service serverreceives a broadcast request message such as an “I need” packet from apeering client on the network, the service server transitions to alocating local aliased copy state 124. In particular, the service serverrefers to its list of local aliased copies to determine if the serviceserver has a local copy of the requested resource or item identified by,for example, an URL/URI. If the service server determines that it doesnot have a local copy of the requested resource, then the service serverreturns to the server idle state 122.

Alternatively, if the service server determines that it has a localcopy, the service server preferably waits a randomly generated delayresponse time period at stage 126. The service server may generate arandom number, such as between 0 and 2000, which the service serverutilizes as the length of time it waits before responding. In onepreferred embodiment, the random number is the number of millisecondsthe service server waits before replying to the request. While theservice server awaits expiry of the randomly generated delay responsetime period, the service server listens for a broadcast “I found” packetfrom the requesting client corresponding to the received request packet.It is noted that regardless of the state of the service server for agiven peer request, the service server listens for new requests such as“I need” packets. The broadcast “I found” packet from the requestingclient indicates that the requesting client has found the requestedresource. If the service server receives an “I found” packet from therequesting client before expiry of the delay response time period, theservice server transitions to state 128 to cancel the response to therequest and returns to server idle state 122.

Alternatively, if no “I found” packet is received prior to theexpiration of the delay response time period, the service servertransitions to state 130 to transmit an “I have” packet directly to therequesting peer client. The “I have” packet preferably contains a localalias for the requested object on the service server which therequesting peer can access via the HTTP server of the of the serviceserver. Although not preferred, the service server may alternativelybroadcast the “I have” packet over the network rather than transmittingit directly to the requesting client. The service server then returns tothe server idle state 122.

As is evident, the randomly generated delay response time period allowsmultiple peer servers to share loads in an orderly fashion. Inparticular, randomizing the delay response time period ensures that anygiven node would not automatically become the default server to a largeportion of the peers and eliminates any need for the service server toexercise preferences as to which service clients the service server willsupply the requested item. In other words, the random wait time beforeresponding to a request ensures that any one machine does not become anoverloaded server of the item or update to the rest of the network. Inaddition, as a given item is propagated through the network to peers onthe network, the load on any one node is likely further reduced. Thus,the system impact on a given service server as it supplies the requesteditem to service clients can be relatively minimal.

However, it is to be understood that a situation in which multipleservice servers each transmitting an “I have” packet in response to agiven request packet may occur. For example, a first service server maytransmit an “I have” packet upon expiry of its delay response timeperiod. The “I found” packet transmitted or to be transmitted by therequesting peer corresponding to the first “I have” packet may notarrive at the second service server prior to the expiry of its delayresponse time period, causing the second service server to transmit an“I have” upon expiry of its delay response time period. In such asituation where the requesting client receives multiple “I have” packetsfrom multiple service servers, the requesting client may simply processthe first “I have” response and ignore any subsequent “I have” packetsit may receive.

FIGS. 4A and 4B are alternative state diagrams illustrating states 140,140A of a typical peering service client in making a given request for aresource over the peer-to-peer network. Referring to FIG. 4A, initially,the service client is in an idle state 142. When a service client needsa desired resource, such as an Internet resource, the service clientgenerates and broadcasts an “I need” packet over the peer-to-peernetwork. For example, the “I need” request may specify an URL (e.g.,http://something.tld/someother/thing/here), a protocol (e.g., HTTPprotocol), a desired operation (e.g., get operation), and that therequesting peer only wants cached objects.

After broadcasting the “I need” request, the service client transitionsto a waiting for response state 144 in which the service client awaits amaximum delay response time period plus a transmission time period for aresponse from any of the service servers. In the example above where therandomly generated delay response time period ranges between 0 and 2000milliseconds, the client response waiting time period would be, forexample, 2200 milliseconds to allow for a 200 millisecond transmissiontime period.

If an “I have” response is received from a service server during theclient response waiting time, then the service client transitions tostate 146 and generates and broadcasts an “I found” message over thenetwork to inform all other peers that the desired resource or item hasbeen found. The service client then transitions to the requested itemfound state 158. The service-enabled application requesting the itemthen retrieves the requested item from the responding service server atthe location within the network as specified in the received “I have”packet. Generally, the service-enabled application retrieves therequested item through the local HTTP server using, for example, port6515. Once the service-enabled application successfully retrieves therequested item, the service client informs the service server running onthe same machine that a local copy of the resource now exists. Theservice client then returns to the idle state 142.

Alternatively, if no response is received during the client responsewaiting time, the service client times out and transitions to state 150to retrieve the requested item itself such as via the Internet. Once theretrieval is complete, the service client transitions to found itemstate 158 in which the service client informs the service server runningon the same computer or at the same node that a local copy of theresource now exists. The service client then returns to client idlestate 142. As is evident, regardless of whether the service clientreceived an “I have” packet from a service server on the network, theclient machine can itself become a service server for the requestedresource after successful completion of its request.

FIG. 4B illustrates the 140A states of a typical service in a preferredalternative embodiment particularly suitable for applications thatinclude downloading of files. States 140A includes the states as shownand described with reference to FIG. 4A plus additional states fordealing with currently in-progress downloads of the requested item byother peers. These additional states allow a peer node to completedownloading the requested resource and then distribute it immediatelyand automatically upon download completion to the requesting serviceclient.

In particular, instead of directly transitioning to state 150 toretrieve the requested item itself after the service client times outthe request, the service client transitions to “wait for download?”state 144 in which the service client determines whether it can or willwait for completion of any in-progress download of the requested item byanother peer. If not, then the service client transitions to state 150to retrieve the requested item itself and continues with statetransitions similar to that described above with reference to FIG. 4A.

If the service client determines that it can or will wait for thecompletion of any in-progress download, the service client transitionsto “any in-progress downloads?” state 152. If there are no suchin-progress downloads of the requested item, then the service clienttransitions to state 150 to retrieve the requested item itself andcontinues with state transitions similar to that described above withreference to FIG. 4A.

Alternatively, if there is at least one in-progress download of therequested item, then the service client transitions to state 154 inwhich it generates and broadcasts an “I found” message. The serviceclient then transitions to state 156 to await completion of thein-progress download of the requested item. Upon completion of thein-progress download of the requested item, the service clienttransitions to the requested item found state 158. The service clientretrieves the requested item from the local location within the network.After successful completion of its request, the service client willinform the service server running on the same machine that a local copyof the resource now exists. The service client then returns to the idlestate 142.

As is evident, in order for the service client to determine if there areany in-progress downloads in state 152, a service client that isdownloading a file for a service-enabled application preferablybroadcasts a “downloading” message and/or directly responds to theclient server of a broadcast “I need” request with a “I am downloading”rather than an “I have” response message. In one preferred embodiment,the service client may set a downloading flag for the corresponding fileto true.

In addition, the service-enabled application preferably transmitsperiodic progress packets to any node that is waiting for the resourcebeing downloaded such that those nodes may interactively displaydownload progress information to end users at state 156. Alternatively,the service-enabled application may broadcast such periodic downloadprogress packets over the network. Thus, a node in the retrieve itemstate 150 preferably periodically transmits a “downloading” message thatincludes progress information.

Service Functionality and Service Packet Format

One functionality provided by the peering service is that of a centralclearing house for formatting, sending, receiving and decoding servicepackets, such as for “I need,” “I found,” and “I have” packets. In otherwords, the peering service manages the peer-to-peer communicationprocess for obtaining requested items. The specific functionalityinvoked by a given service packet itself is generally dependent on thespecific service-enabled application.

The communication protocol used in broadcasts (e.g., “I need” and “Ifound” packets) and responses (e.g., “I have” packets) is typicallyTCP/IP. Each packet is typically approximately 200 bytes in size andcontains the node ID of the sender as well as any other suitableinformation. Transfer of the requested item from the service server tothe service client is typically via HTTP.

The service packet format is preferably based upon the well-accepted andwidely utilized XML format. For example, an XML service packet formatmay include a service identification and various key-value pairs,including those inserted by the service as well as those defined by thecorresponding service-enabled application.

Various key-value pairs may be inserted by the peering service into eachservice packet. Examples of suitable key-value pairs includeidentification, type, and version key-value pairs. Specifically, anidentification key-value pair identifies each request and responsescorresponding to the request. In general, the identification value isunique on the originating node but need not be unique on the network asa whole. The range of values for the identification value may dependupon the number of bits assigned thereto. For example, 32 bits or fouroctets may be assigned to the identification value and thus theidentification value would range from 0 to 2³¹. With respect to the typekey-value pair, the type value is typically either request, end-request,response, and/or any application-defined value. Any other suitableapplication-defined key-value pairs may also be includes in the servicepacket.

An exemplary service packet may be:

<service type = “request” version = “1.0” ID = “1111” method = “get”href = “http:/domain.com/whatever” acceptprotocol = “http”/>

FIG. 5 is a flowchart illustrating a typical process 180 of a peeringservice server in processing a request from a peering client in thepeer-to-peer network. At step 182, the service server is listening on adesignated port for a broadcast request message from a peer client onthe network. At step 184, the service server receives a broadcastrequest message on the designated port such as an “I need” packet from apeering client on the network. At step 186, the service serverdetermines if it has a local aliased copy of the requested item. Inparticular, the service server refers to its list of local aliasedcopies to determine if the service server has a local version of therequested resource or item, such as an URL/URI.

If the service server determines that it does not have a local copy ofthe requested resource, then the process 180 is complete. Alternatively,if the service server determines that it has a local copy, the serviceserver preferably waits a randomly generated delay response time periodwhile listening for a broadcast “I found” packet from the requestingclient corresponding to the received request packet at step 188. Asdiscussed above, the service server may generate a random number between0 and 2000 as the length of time in milliseconds it waits beforeresponding. The broadcast “I found” packet from the requesting clientindicates that the requesting client has found the requested resource.

It is noted that throughout the process 180, the service server ispreferably continuously listening for any additional broadcast requestmessages and performs process 180 for each received broadcast requestmessage as they are received.

If the service server receives an “I found” packet from the requestingclient before expiry of the delay response time period, the serviceserver cancels the response to the request at step 190 and the process180 is complete. Alternatively, if no “I found” packet is received priorto the expiration of the delay response time period, the service servertransmits an “I have” packet directly to the requesting peer client atstep 192 and the server process 180 is complete. The “I have” packetpreferably contains a local alias for the requested object on theservice server.

FIG. 6 is a flowchart illustrating a typical process 200 of a peeringservice client in requesting a resource over the peer-to-peer network.At step 202, the service client generates and broadcasts an “I need”packet over the peer-to-peer network on a designated port. At step 204,the service awaits for a response from any of the service servers on thenetwork for a period equal to a client response waiting time period,typically a maximum delay response time period plus a transmission timeperiod.

If an “I have” response is received from a service server during theclient response waiting time, then the service client generates andbroadcasts an “I found” message over the network at step 206. Theservice-enabled application requesting the item then retrieves therequested item from the responding service server at the location withinthe network as specified in the received “I have” packet at step 208.Once the service-enabled application successfully retrieves therequested item, the service client informs the service server running onthe same machine that a local copy of the resource now exists at step210. The process 200 is then complete.

Alternatively, if no response is received during the client responsewaiting time, i.e., the service client times out, the service clientdetermines if the service-enabled application can or will wait forcompletion of any in-progress download of the requested item by anotherpeer at step 214. If not, the service client retrieves the requesteditem itself such as via the Internet at step 216 and then proceeds tostep 210 to complete the process 200.

If the service client determines that it can or will wait for thecompletion of any in-progress download, the service client determineswhether there are any in-progress downloads at step 220. If there are nosuch in-progress downloads of the requested item, the service clientthen proceeds to step 210 to complete the process 200.

If there is at least one in-progress download of the requested item,then the service client generates and broadcasts an “I found” message atstep 222. The service client then awaits completion of the in-progressdownload of the requested item at step 224. For example, the serviceclient may receive an “I have” or a “Download complete” message from thedownloading peer.

Upon completion of the in-progress download of the requested item, theservice client retrieves the requested item from the local locationwithin the network at step 226. After successful completion of itsrequest, the service client then proceeds to step 210 to complete theprocess 200. It is noted that steps 214 and 220-226 can be optional andpreferably implemented for applications that include downloading offiles

As is evident, in order for the service client to determine if there areany in-progress downloads at step 220, a service client that isdownloading a file for a service-enabled application from outside of thenetwork, e.g., from the Internet, notifies its peers on the network thata downloading process is in progress. For example, FIG. 7 is a flowchartillustrating a preferred embodiment of the retrieve step 216 in moredetail.

As shown, the service client begins retrieving the requested item atstep 216A. At step 216B, the service client may broadcast a“downloading” message and/or directly respond with a “I am downloading”response message to any client server that transmitted a broadcast “Ineed” request. In addition, the service client preferably alsoperiodically transmits progress packets at step 216C either by broadcastor by direct transmission to any node that is waiting for the resourcesuch that those nodes may interactively display download progressinformation to end users at those nodes. Alternatively, steps 216B and216C may be combined into a single periodic packet transmission in whicheach packet is a “downloading” message that includes progressinformation.

Service-Enabled Product Updating Application

One exemplary implementation of the peering service described herein isa product updating service implementation and a service-enabledapplication having a shared agent. The agent is shared by an anti-virusapplication and a firewall application. The peering service isencapsulated in a single DLL that contains components for performing anupdate service, namely, a peering server having an HTTP server, apeering client, and a product updating service.

The product updating service determines what updates, if any, torequest. If the product updating service determines that an update isnecessary, the service client broadcasts an “I need” packet to request aspecific URL for the necessary product updates. In other words, thepeering service provides a mechanism for keeping service-enabledapplication, its engine, and its virus signature files up-to-date.

In particular, when a first computer or node boots, its product updaterbroadcasts an “I need” packet requesting for myupdate.cab file at aspecified URL. The myupdate.cab file, e.g., approximately 7-8 k in size,contains a script with instructions on how to check the current versionof the product, engine, and virus signature files against the latestavailable version so that the product updater can determine if an updateis necessary. This file may not be cacheable, so the service servers maynot be able to offer it and can instead be obtained directly via theInternet.

If the product updating service determines, based on the myupdate.cabfile, that an update is necessary, the product updating service, via thepeering service, broadcasts an “I need” packet over the network. Anupdate may include engine, DAT, and/or product updates. For any updatefiles that are downloaded, whether directly from the Internet and/orfrom one or more of the peers on the network, the product updatingservice preferably checks to ensure that the updates have been digitallysigned. Once the updates are authenticated, they are installed at therequesting node.

The product update service checks for updates at any suitablepre-defined intervals and/or upon occurrence of various events. Forexample, the product update service may check for updates upon boot or 5minutes after boot, 6 hours after each unsuccessful check, and/or upon ascheduled basis such as once a day, once every 12 hours after eachsuccessful check.

An update can include virus signature files (DATs), engine, and/orproduct update. DATs are typically updated weekly, such on a particularday of the week and are approximately 900-950 k in size on average. Theengine is usually updated every 2 to 3 months and is approximately550-600 k in size on average. The product is updated as hotfixes becomeavailable, typically every 6-8 weeks, or as new versions becomeavailable, typically every 4-6 months, and is approximately 700-750 k insize on average.

In the current example, a complete update, including engine, virussignature files and product, comprises of six *.cab files, totalingapproximately 2.25M. The six *.cab files for an update and theirrespective average sizes are listed below:

Myavdat.YYMMDDHHMM.cab average 910k Myxtrdat.YYMMDDHHMM.cab average 16kMycioagt.YYMMDDHHMM.cab average 370k Vsasap.YYMMDDHHMM.cab average 360kVseng9x.YYMMDDHHMM.cab average 240k Vsengine.YYMMDDHHMM.cab average 340k

As any number of these *.cab files may need to be updated, each file ispreferably requested via the peering service in a separate transaction.Thus, some or all of the needed *.cab file may be pulled from differentnodes and/or the Internet.

FIG. 8 is a flowchart illustrating an exemplary secure product updatingprocess 240 implemented by a service-enabled product updatingapplication over a peer-to-peer network. At step 242, theservice-enabled product updating application retrieves a catalogcontaining a listing of files for a current version of the product. Atstep 244, the service-enabled product updating application comparesinformation contained in the catalog with versions currently installedat the node to determine if an update is needed. If a newer version isavailable, then the service-enabled product updating applicationretrieves the newer version at step 246. Otherwise, the process 240terminates.

Preferably, the newer version is located at a unique URL that isdetermined by the specific version to enables update to request aspecific URL different from the URL the application used last time whenit installed the currently installed version. For example, the uniqueURL may be generated by including an encoding of a timestamp in the filename such that a file named VsASaP.CAB would namedVsASaP.200101131511.CAB if it were released on Jan. 13, 2001 at 3:11 PM.

The unique naming of URLs is desirable because the service-enabledproduct updating application attempts to locate local copies of specificURLs. Thus, the updating application may not be able differentiatebetween a cached copy of an old VsASaP.CAB file and a copy of a mostrecent version of the VsASaP.CAB file without the additional versioninformation encoded into the file name. With this unique file name, theupdating application can ask the service to look for a copy ofVsASaP.200101131511.CAB on the local network segment with assurance thatit will obtain the desired file as listed in the update catalog.

The product updating application preferably verifies the integrity ofthe retrieved data at step 248. Such integrity verification is highlydesirable particularly where the retrieved data may be actual executablebinaries. Moreover, with data packets containing potentially criticaldata such as anti-virus product updates and signature files being passedaround in a network, security is of great concern. In addition,peer-to-peer distribution is more susceptible to attacks since thedistributor of the data files does not have control of the peer serversthat are passing the files around. Thus, the service-enabled updatingapplication preferably implements digital signature and versioninformation security measures at step 248 to ensure that the update isnot compromised and are versioned properly.

In particular, step 248 may include verifying that contents of aretrieved data file signed with a digital signature or certificate havenot been altered with use of digital signature security measure.Specifically, the digital signature is authenticated to verify that thefile contents have not been altered after it was downloaded from theoriginal source, i.e., verify the authenticity of the file. Any suitabledigital signature authentication tool such as the 1024-bit VeriSigncertificate may be utilized.

As another desired security measure, step 248 may additionally oralternatively include a version information security measure to guardagainst a retrieved data file that has been renamed from successfullymasquerading as the specified file. Because the file name is utilized toindicate the version of the file, an old file may have been renamed asthe requested file. The compromised file may be signed and unaltered andyet its contents would potentially be outdated or incompatible with thecurrent version. Thus, a version information security measure ispreferred.

According to a preferred embodiment, the version information securitymay be implemented by encoding an additional block of data containingversion information within the digitally signed file such that theadditional encoded data can be utilized to verify the file is indeed thedesired file. In the case of product updating, a cabinfo.ini file isoptionally added to the MyUpdate.cab to specify the original file namefor the package. Thus, if an older file on the service server wasrenamed to match the current update filename, the embedded filedescription in that file would not match the one included in theMyUpdate.cab file on the client and the update file would be rejected.

Finally, at step 250, the product updating application installs theupdate package at the node.

As illustrated in the description above, the peering service facilitatesin reducing or minimizing the number of service clients that have toobtain files or other resources such as product update files via theInternet by using secure, peer-to-peer communication to distribute thefiles among client machines on a network, such as a LAN, via anintranet. The peering service enables secure, automatic distribution ofthe update files between service clients, independent of a networkadministrator or end-user, to keep the anti-virus and firewallapplication/service up-to-date with minimal impact to network bandwidth.

Often, many computers on a network do not have the most up-to-dateanti-virus and/or firewall files. Using the secure peering serviceallows for automatic and secure updating of such files and also reducesor eliminates the need for a network administrator to script anti-virusfile updates. Furthermore, by efficiently spreading load and utilizingresources across a local network over a high-speed LAN, a bandwidthcrunch resulting from the computers pulling update files from theInternet is largely reduced. Thus, the peering service allows for easeof distribution of product upgrades and updates with a minimal number ofcomputers requiring to connect to the Internet to obtain the necessaryfiles resulting in a reduced usage of Internet bandwidth.

The peering service also allows a given client to pull the data filesfrom any node on the network, rather than having to connect to acentralized server that might require several additional network hops,resulting in an optimal use of network bandwidth to distribute updates.

FIGS. 9 and 10 illustrate a schematic and a block diagram, respectively,of an example of a general purpose computer system 1000 suitable forexecuting software programs that implement the methods and processesdescribed herein. The architecture and configuration of the computersystem 1000 shown and described herein are merely illustrative and othercomputer system architectures and configurations may also be utilized.

The illustrative computer system 1000 includes a display 1003, a screen1005, a cabinet 1007, a keyboard 1009, and a mouse 1011. The mouse 1011can have one or more buttons for interacting with a GUI (graphical userinterface) that may be displayed on the screen 1005. The cabinet 1007typically house one or more drives to read a computer readable storagemedium 1015, system memory 1053, and a hard drive 1055, any combinationof which can be utilized to store and/or retrieve software programsincorporating computer codes that implement the methods and processesdescribed herein and/or data for use with the software programs, forexample. Examples of computer or program code include machine code, asproduced, for example, by a compiler, or files containing higher levelcode that may be executed using an interpreter.

Computer readable media may store program code for performing variouscomputer-implemented operations and may be encompassed as computerstorage products. Although a CD-ROM and a floppy disk 1015 are shown asexemplary computer readable storage media readable by a correspondingCD-ROM or floppy disk drive 1013, any other combination of computerreadable storage media can be utilized. Computer readable mediumtypically refers to any data storage device that can store data readableby a computer system. Examples of computer readable storage mediainclude tape, flash memory, system memory, and hard drive mayalternatively or additionally be utilized. Computer readable storagemedia may be categorized as magnetic media such as hard disks, floppydisks, and magnetic tape; optical media such as CD-ROM disks;magneto-optical media such as floptical disks; and specially configuredhardware devices such as application-specific integrated circuits(ASICs), programmable logic devices (PLDs), and ROM and RAM devices.Further, computer readable storage medium may also encompass datasignals embodied in a carrier wave, such as the data signals embodied ina carrier wave carried in a network. Such a network may be an intranetwithin a corporate or other environment, the Internet, or any network ofa plurality of coupled computers such that the computer readable codemay be stored and executed in a distributed fashion.

Computer system 1000 comprises various subsystems. The subsystems of thecomputer system 1000 may generally include a microprocessor 1051, systemmemory 1053, fixed storage 1055 (such as a hard drive), removablestorage 1057 (such as a CD-ROM drive), display adapter 1059, sound card1061, transducers 1063 (such as speakers and microphones), networkinterface 1065, and/or scanner interface 1067.

The microprocessor subsystem 1051 is also referred to as a CPU (centralprocessing unit). The CPU 1051 can be implemented by a single-chipprocessor or by multiple processors. The CPU 1051 is a general purposedigital processor which controls the operation of the computer system1000. Using instructions retrieved from memory, the CPU 1051 controlsthe reception and manipulation of input data as well as the output anddisplay of data on output devices.

The network interface 1065 allows CPU 1051 to be coupled to anothercomputer, computer network, or telecommunications network using anetwork connection. The CPU 1051 may receive and/or send information viathe network interface 1065. Such information may include data objects,program instructions, output information destined to another network. Aninterface card or similar device and appropriate software implemented byCPU 1051 can be used to connect the computer system 1000 to an externalnetwork and transfer data according to standard protocols. In otherwords, methods and processes described herein may be executed solelyupon CPU 1051 and/or may be performed across a network such as theInternet, intranet networks, or LANs (local area networks), inconjunction with a remote CPU that shares a portion of the processing.Additional mass storage devices (not shown) may also be connected to CPU1051 via the network interface 1065.

The subsystems described herein are merely illustrative of thesubsystems of a typical computer system and any other suitablecombination of subsystems may be implemented and utilized. For example,another computer system may also include a cache memory and/oradditional processors 1051, such as in a multi-processor computersystem.

The computer system 1000 also includes a system bus 1069. However, thespecific buses shown are merely illustrative of any interconnectionscheme serving to link the various subsystems. For example, a local buscan be utilized to connect the central processor to the system memoryand display adapter.

While the preferred embodiments of the present invention are describedand illustrated herein, it will be appreciated that they are merelyillustrative and that modifications can be made to these embodimentswithout departing from the spirit and scope of the invention. Thus, theinvention is intended to be defined only in terms of the followingclaims.

1. A method for securely sharing resources over a peer-to-peer network, comprising: broadcasting a single request to a plurality of peers by a requesting peer for a resource over the peer-to-peer network wherein the request contains an identification of the resource and the resource identification contains a resource version identifier; receiving a response from a responding peer on the peer-to-peer network indicating that the responding peer has the requested resource; retrieving the requested resource from the responding peer; periodically broadcasting a single progress message including progress information to the plurality of peers indicating that the requested resource is in the process of being retrieved; verifying the retrieved resource by ensuring the retrieved resource contains the version identifier embedded therein; and informing a service server on the responding peer that a local copy of the retrieved resource now exists; wherein a file name of the retrieved resource indicates a version of the retrieved resource, a file added to the retrieved resource specifies an original name of the retrieved resource, and the original name is utilized to verify the file name of the retrieved resource.
 2. The method for securely sharing resources over a peer-to-peer network of claim 1, wherein said verifying the retrieved resource further comprises verifying a digital signature of the retrieved resource to ensure integrity of the retrieved resource.
 3. The method for securely sharing resources over a peer-to-peer network of claim 2, wherein said digital signature is a 1024-bit VeriSign digital certificate.
 4. The method for securely sharing resources over a peer-to-peer network of claim 1, further comprising installing said resource.
 5. The method for securely sharing resources over a peer-to-peer network of claim 1, further comprising retrieving a catalog containing a listing of resources.
 6. The method for securely sharing resources over a peer-to-peer network of claim 5, further comprising comparing the listing of resources with resources installed at the requesting peer to determine which resources are to be requested over the peer-to-peer network.
 7. The method for securely sharing resources over a peer-to-peer network of claim 6, further comprising requesting each resource to be requested in a separate transaction such that each resource to be requested may be retrieved from a same or different responding peer.
 8. The method for securely sharing resources over a peer-to-peer network of claim 1, wherein the responding peer scans a list of local aliased copies to determine if the responding peer has a local version of the requested resource.
 9. The method for securely sharing resources over a peer-to-peer network of claim 1, wherein the responding peer waits a predetermined period of time before responding that the responding resource has the requested resource.
 10. The method for securely sharing resources over a peer-to-peer network of claim 9, wherein the predetermined period of time is randomly generated between 0 and 2000 milliseconds.
 11. The method for securely sharing resources over a peer-to-peer network of claim 1, wherein, after receiving the response, the requesting peer broadcasts a message to the plurality of peers that the requested resource has been found.
 12. A product updating service, comprising: automatically downloading a catalog containing a current listing of resources for a product at a predetermined time, each resource being identified by a resource version identifier; comparing the listing of resources in the catalog with resources installed at a node of a peer-to-peer network to determine which resources are to be requested over the peer-to-peer network; requesting each resource to be requested in a separate transaction over the peer-to-peer network, the request being made via a single broadcasted request to a plurality of peers; retrieving each resource to be requested in the peer-to-peer network and the Internet; periodically broadcasting, for each requested resource, a single progress message including progress information to the plurality of peers indicating that the requested resource is in the process of being retrieved; verifying each retrieved resource by ensuring the retrieved resource contains the version identifier embedded therein; and informing a service server on the responding peer that a local copy of each retrieved resource now exists; wherein the product updating service is operable such that, for each retrieved resource, a file name of the retrieved resource indicates a version of the retrieved resource, a file added to the retrieved resource specifies an original name of the retrieved resource, and the original name is utilized to verify the file name of the retrieved resource.
 13. The product updating service of claim 12, wherein said verifying each retrieved resource further comprises verifying a digital signature of each retrieved resource to ensure integrity of the retrieved resource.
 14. The product updating service of claim 13, wherein said digital signature is a 1024-bit VeriSign digital certificate.
 15. The product updating service of claim 12, further comprising installing each of the retrieved resources.
 16. The product updating service of claim 12, wherein each resource is digitally signed with a digital signature.
 17. The product updating service of claim 16, wherein said digital signature is a 1024-bit VeriSign digital certificate.
 18. A computer program product, comprising: computer code that broadcasts a single request to a plurality of peers by a requesting peer for a resource over a peer-to-peer network wherein the request contains an identification of the resource and the resource identification contains a resource version identifier; computer code that receives a response from a responding peer on the peer-to-peer network indicating that the responding peer has the requested resource; computer code that retrieves the requested resource from the responding peer; computer code that periodically broadcasts a single progress message including progress information to the plurality of peers indicating that the requested resource is in the process of being retrieved; computer code that verifies the retrieved resource by ensuring the retrieved resource contains the version identifier embedded therein; computer code that informs a service server on the responding peer that a local copy of the retrieved resource now exists; and a computer readable medium that stores said computer codes; wherein the computer program product is operable such that a file name of the retrieved resource indicates a version of the retrieved resource, a file added to the retrieved resource specifies an original name of the retrieved resource, and the original name is utilized to verify the file name of the retrieved resource.
 19. The computer program product of claim 18, wherein said computer code that verifies the retrieved resource further comprises computer code that verifies a digital signature of the retrieved resource to ensure integrity of the retrieved resource.
 20. The computer program product of claim 19, wherein said digital signature is a 1024-bit VeriSign digital certificate.
 21. The computer program product of claim 18, further comprising computer code that installs said resource.
 22. The computer program product of claim 18, further comprising computer code that retrieves a catalog containing a listing of resources.
 23. The computer program product of claim 22, further comprising computer code that compares the listing of resources with resources installed at the requesting peer to determine which resources are to be requested over the peer-to-peer network.
 24. The computer program product of claim 23, further comprising computer code that requests each resource to be requested in a separate transaction such that each resource to be requested may be retrieved from a same or different responding peer. 